Mobile Regional Airport
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Mobile Regional Airport clear sky chart from 2005-11-05 to 2017-03-25.

This page is a summary of past forecasts. Even though it's based only on forecasts, some people use these pages as clue to a site's climate. But climate data based on actual observation should be preferred (if you can find it!).

Cloud, Transparency and Seeing forecasts are summarized individually. But because good observing conditions require a combination of minimum cloud cover, transparency and seeing, the individual forecast summaries can be difficult to interpret. The observing conditions section counts the combinations of conditions needed for common types of astronomical observation.

Observing Conditions

The following tables count the occurrence of the combinations of forecast and darkness conditions needed for different observations. Conditions are rated by by what percentage of the hours the observation would likely be attempted are usable.
Observation TypeMinimum conditions for hour to be usableOut of hours
Clear of CloudsTransparencySeeingSky Brightness
Planetary:50%(no limit)Average(no limit)Nighttime Hours
Deep Sky:70%Average(no limit)5.9Nighttime Hours
CCD Imaging:70%Below AveragePoor(no limit)Nighttime Hours

Percentages are of nighttime hours per month, or per year, when a particular observing conditions was met. Deep Sky percentages never exceed 50% because the moon is up half the time. Deep sky percentages are much lower for charts at high latitudes because of fewer dark hours in the summer.

Overall

PlanetaryData
Pts
Deep Sky
Max 60%
Data
Pts
Both Planetary and Deep Sky
Max 60%
Data
Pts
Either Planetary or Deep SkyData
Pts
CCD ImagingData
Pts
Night
58%
14582
24%
45330
19%
14537
64%
14537
32%
26769

By Month

MonthDays of MonthPlanetaryData
Pts
Deep Sky
Max 60%
Data
Pts
Both Planetary and Deep Sky
Max 60%
Data
Pts
Either Planetary or Deep SkyData
Pts
CCD ImagingData
Pts
January1st to 15thNight
40%
720
26%
2158
14%
716
51%
716
30%
1317
January16th to endNight
37%
768
26%
2304
15%
768
46%
768
26%
1460
February1st to 15thNight
41%
704
28%
2107
15%
699
53%
699
32%
1251
February16th to endNight
35%
631
23%
1893
13%
631
44%
631
26%
1217
March1st to 15thNight
41%
720
22%
2160
14%
720
48%
720
28%
1366
March16th to endNight
55%
590
27%
1939
22%
590
60%
590
34%
1076
April1st to 15thNight
48%
494
25%
1647
20%
494
57%
494
29%
967
April16th to endNight
62%
495
27%
1650
26%
495
69%
495
41%
843
May1st to 15thNight
64%
494
22%
1649
21%
494
69%
494
34%
929
May16th to endNight
76%
513
22%
1548
22%
513
78%
513
37%
879
June1st to 15thNight
78%
495
14%
1485
15%
495
78%
495
36%
859
June16th to endNight
80%
495
17%
1485
18%
495
80%
495
33%
889
July1st to 15thNight
83%
465
11%
1467
12%
465
83%
465
30%
900
July16th to endNight
81%
522
10%
1632
13%
489
82%
489
28%
1017
August1st to 15thNight
86%
494
12%
1638
15%
491
86%
491
32%
964
August16th to endNight
72%
525
15%
1750
18%
525
73%
525
25%
1116
September1st to 15thNight
74%
528
18%
1683
19%
528
75%
528
28%
1066
September16th to endNight
68%
657
26%
1815
22%
657
69%
657
33%
1115
October1st to 15thNight
70%
660
34%
1815
27%
660
73%
660
48%
971
October16th to endNight
60%
704
36%
2086
29%
704
68%
704
45%
1086
November1st to 15thNight
61%
700
32%
2243
29%
700
68%
700
38%
1203
November16th to endNight
53%
720
31%
2340
26%
720
63%
720
36%
1261
December1st to 15thNight
45%
720
26%
2340
21%
720
53%
720
29%
1385
December16th to endNight
37%
768
21%
2496
14%
768
46%
768
22%
1632

Individual Forecasts

The length of each colored bar in the "occurrence of each Forecast" column is proportional to the number of times the chart forecast that color. The percentages are of the total number of hours per month, or per year, with a particular forecast. The colors as the same as those used in clear sky charts.

Note: Transparency probabilities are only counted for those hours that have 30% or less cloud cover. Seeing probabilities are only counted for those hours that have 80% or less cloud cover. If that's too tricky, try Observing Conditions instead.

Overall

Occurrence of each ForecastData
Points
Cloud CoverDay
11%5%25%5%35%5%6%8%40%
45588
Night
10%42442445%8%47%
45555
TransparencyDay
39%6%11%18%16%6%
45309
Night
33%5%13%19%18%8%
45338
SeeingDay
11%311%21%28%22%
4372
Night
11%417%30%28%7%
14585

By Month

Percentage Cloud Cover SE (2006-)
Color Meanings:
Overcast 90% covered 80% covered 70% covered 60% covered 50% covered 40% covered 30% covered 20% covered 10% covered Clear
MonthDays in MonthOccurrence of each ForecastData
Points
January1st to 15thDay
12%5%245%3335%6%45%
1777
16th to endDay
19%6%3432333446%
1920
February1st to 15thDay
14%414324347%46%
1750
16th to endDay
15%435%42435%6%42%
1580
March1st to 15thDay
16%42442445%7%43%
1800
16th to endDay
12%5%24434447%45%
2158
April1st to 15thDay
13%435%5%25%47%7%40%
1971
16th to endDay
10%5%234245%5%8%47%
1980
May1st to 15thDay
11%425%436%46%9%40%
1971
16th to endDay
7%426%6%36%5%7%7%42%
2211
June1st to 15thDay
7%425%7%46%7%9%11%31%
2145
16th to endDay
6%327%7%5%7%8%9%11%30%
2145
July1st to 15thDay
8%5%38%8%5%8%8%8%9%23%
2063
16th to endDay
8%7%36%7%5%9%7%9%11%23%
2108
August1st to 15thDay
8%5%25%8%5%8%8%10%11%26%
1980
16th to endDay
13%6%36%7%46%7%6%8%29%
2100
September1st to 15thDay
10%5%36%7%46%7%8%7%31%
1936
16th to endDay
8%5%35%436%5%46%45%
1815
October1st to 15thDay
7%424323346%55%
1815
16th to endDay
9%32333345%5%56%
1782
November1st to 15thDay
9%424323347%56%
1613
16th to endDay
7%324434336%55%
1620
December1st to 15thDay
13%6%25%434346%45%
1620
16th to endDay
20%8%35%5%24346%34%
1728
January1st to 15thNight
14%5%24424345%48%
2158
16th to endNight
18%5%2432434445%
2304
February1st to 15thNight
13%423314346%50%
2103
16th to endNight
16%6%24424445%44%
1893
March1st to 15thNight
13%6%3442445%6%43%
2160
16th to endNight
11%423314346%52%
1939
April1st to 15thNight
11%424425%5%5%7%46%
1647
16th to endNight
7%313323348%57%
1650
May1st to 15thNight
9%33432446%8%49%
1649
16th to endNight
5%4144245%6%12%48%
1548
June1st to 15thNight
3314436%6%8%14%42%
1485
16th to endNight
3325%5%36%6%8%13%42%
1485
July1st to 15thNight
4214436%8%8%12%41%
1564
16th to endNight
32246%36%7%8%14%38%
1752
August1st to 15thNight
3223446%7%10%15%39%
1650
16th to endNight
7%4346%35%6%7%10%40%
1750
September1st to 15thNight
7%5%25%5%36%7%8%11%37%
1683
16th to endNight
9%5%25%4245%6%7%45%
1815
October1st to 15thNight
5%313412447%60%
1815
16th to endNight
10%213213246%61%
2086
November1st to 15thNight
7%41442335%5%56%
2243
16th to endNight
8%42432345%5%55%
2340
December1st to 15thNight
13%5%24433446%47%
2340
16th to endNight
18%7%35%424446%37%
2496

Transparency (when cloud cover <= 30%)
Color Meanings:
Too cloudy to forecast Poor Below Average Average Above average Transparent
MonthDays in MonthOccurrence of each ForecastData
Points
January1st to 15thDay
38%27%17%22%11%
1778
16th to endDay
42%3416%23%9%
1920
February1st to 15thDay
36%39%17%21%11%
1752
16th to endDay
41%36%17%22%8%
1580
March1st to 15thDay
39%5%7%21%19%7%
1800
16th to endDay
37%410%18%21%7%
2159
April1st to 15thDay
39%5%8%19%18%8%
1971
16th to endDay
32%5%10%25%19%6%
1980
May1st to 15thDay
36%6%12%21%15%7%
1971
16th to endDay
35%6%14%24%16%2
2215
June1st to 15thDay
37%9%16%24%10%1
2145
16th to endDay
40%9%19%20%9%
2145
July1st to 15thDay
49%11%22%12%3
1931
16th to endDay
47%10%20%17%3
1965
August1st to 15thDay
43%10%22%14%8%
1968
16th to endDay
48%9%17%14%7%2
2100
September1st to 15thDay
43%9%16%16%10%3
1936
16th to endDay
37%6%11%19%17%7%
1815
October1st to 15thDay
28%49%17%24%15%
1815
16th to endDay
28%3415%26%19%
1782
November1st to 15thDay
29%27%18%30%11%
1613
16th to endDay
30%36%17%25%16%
1620
December1st to 15thDay
39%37%20%21%6%
1620
16th to endDay
49%45%18%16%4
1728
January1st to 15thNight
38%27%15%24%10%
2158
16th to endNight
42%35%14%23%10%
2304
February1st to 15thNight
34%35%19%22%13%
2112
16th to endNight
41%45%15%20%12%
1893
March1st to 15thNight
40%49%17%21%6%
2160
16th to endNight
32%211%21%22%9%
1939
April1st to 15thNight
35%5%13%17%19%8%
1647
16th to endNight
26%311%26%23%7%
1650
May1st to 15thNight
32%5%15%21%19%6%
1650
16th to endNight
27%8%18%25%19%2
1550
June1st to 15thNight
27%9%26%23%11%1
1485
16th to endNight
30%8%22%25%11%
1485
July1st to 15thNight
29%13%33%17%6%
1467
16th to endNight
30%14%30%20%2
1632
August1st to 15thNight
27%12%33%19%5%
1638
16th to endNight
35%12%25%15%7%3
1750
September1st to 15thNight
34%10%22%17%11%4
1683
16th to endNight
34%5%14%20%15%8%
1815
October1st to 15thNight
23%411%21%22%16%
1815
16th to endNight
25%25%16%26%23%
2086
November1st to 15thNight
28%36%18%29%13%
2243
16th to endNight
29%45%19%22%18%
2340
December1st to 15thNight
37%49%21%21%6%
2340
16th to endNight
46%47%20%15%6%
2496

Seeing (when cloud cover <= 80%)
Color Meanings:
Too cloudy to forecast Bad 1/5 Poor 2/5 Average 3/5 Good 4/5 Excellent 5/5
MonthDays in MonthOccurrence of each ForecastData
Points
January1st to 15thDay
22%5%26%26%12%6%
90
16th to endDay
15%15%39%18%10%
96
February1st to 15thDay
14%12%33%22%14%3
90
16th to endDay
12%6%40%25%14%
81
March1st to 15thDay
21%7%37%27%41
90
16th to endDay
16%6%20%29%24%1
216
April1st to 15thDay
20%8%20%23%23%3
210
16th to endDay
14%317%32%27%5%
210
May1st to 15thDay
9%216%28%30%11%
228
16th to endDay
10%17%27%26%26%
267
June1st to 15thDay
9%3221%29%33%
255
16th to endDay
5%1214%30%45%
255
July1st to 15thDay
8%118%34%45%
245
16th to endDay
5%1110%37%44%
270
August1st to 15thDay
7%19%39%41%
253
16th to endDay
10%14%41%33%
268
September1st to 15thDay
9%414%34%35%
255
16th to endDay
11%228%34%22%
254
October1st to 15thDay
7%11%26%38%15%
255
16th to endDay
11%38%31%26%18%
118
November1st to 15thDay
18%116%35%23%4
90
16th to endDay
8%7%31%32%14%5%
90
December1st to 15thDay
10%5%37%32%12%2
90
16th to endDay
31%6%18%23%16%3
96
January1st to 15thNight
16%7%30%33%10%
720
16th to endNight
20%9%26%34%8%
768
February1st to 15thNight
15%7%32%33%10%
704
16th to endNight
18%8%31%32%8%
631
March1st to 15thNight
16%8%27%35%10%
720
16th to endNight
12%5%22%38%20%1
590
April1st to 15thNight
13%5%24%37%17%1
494
16th to endNight
10%319%42%23%
495
May1st to 15thNight
10%213%39%31%2
495
16th to endNight
6%7%30%47%6%
515
June1st to 15thNight
4329%48%12%
495
16th to endNight
41217%52%21%
495
July1st to 15thNight
4112%53%28%
465
16th to endNight
3112%49%31%
522
August1st to 15thNight
37%53%33%
494
16th to endNight
10%112%50%23%
525
September1st to 15thNight
8%2315%47%22%
528
16th to endNight
11%25%28%43%8%
657
October1st to 15thNight
8%13%35%36%6%
660
16th to endNight
10%319%31%29%5%
704
November1st to 15thNight
8%318%41%23%4
700
16th to endNight
11%5%23%38%19%1
720
December1st to 15thNight
15%7%27%32%16%1
720
16th to endNight
21%5%29%30%12%
768
Page generated at 2017-03-26 12:16:43. Version ac04

Copyright 2017 A. Danko


Mobile Regional Airport Clear Sky Chart | Charts Home